2

1 Death Tyrant

3

Roll 1d3+1 Cloakers

4

Roll 2d4 Umber Hulks

5

1 Yochlol with Roll 1d4+2 Drow Elite Warriors

6

Roll 2d4 Salamanders

7

Roll 1d2+1 Aboleth with Roll 1d4 Chuul

8

1 Beholder

9

Roll 1d3+1 Fomorians

10

1 Drow Priestess of Lolth with Roll 2d4 Drow Elite Warriors

11

Roll on "Underdark Medium" (lower-level encounter)

12

1 Purple Worm

13

Roll 2d4 Stone Giants

14

Roll 1d3 Mind Flayers and 1 Mind Flayer Arcanist

15

1 Dao with Roll 1d3 Earth Elementals

16

1 Behir

17

Roll 2d4 Xorns

18

Roll 1d4+1 Fire Giants

19

1 Beholder and Roll 2d4 Duergar

20

1 Young Red Shadow Dragon